sound deadening questions

I think i'm going to get rid of my spare (yes i know.. i'll just cross my fingers and hope nothing will happen. shush murphy.) And in the area where it goes I'm going make a fiberglass enclosure and mount my 2 amps + my carputter (I will add a window but that's beside the point). Now I will be adding some sound deading to most parts of the car (because i will need it) and my question is.. do i need it on the floor below my fiberglass enclosure?

I'm pretty sure i would have to put something underneath to give it a cushion so it doesnt vibrate, however as far as I understand when dynamat or any equiv. product is installed it's pretty hard correct? So even if I do install it i would need something else to create a cushion?

What do you guys think?

I've read that it is usually recommended that you do the floor also, but curious to see some responses...

The idea behind dynamat type products is to prevent the sheet metal from vibrating.

If you want to save some $$$, go to the local building supply store and ask for Icegard or Resisto membrane. (the resisto membrane is available with an aluminium foil on one side and self adhesive on the other).

It is available in 39 inch wide Rolls X 33 feet long (107.6 square feet) for around $60 plus taxes.

Those product are alot less money then Dynamat and my experience when I did my 2000 Odyssey EX with the resisto brand, it improved the sounds from the speakers and reduced road noise.

Best regards

frenchnew

Originally Posted by [iG]

I think i'm going to get rid of my spare (yes i know.. i'll just cross my fingers and hope nothing will happen. shush murphy.) And in the area where it goes I'm going make a fiberglass enclosure and mount my 2 amps + my carputter (I will add a window but that's beside the point). Now I will be adding some sound deading to most parts of the car (because i will need it) and my question is.. do i need it on the floor below my fiberglass enclosure?

I'm pretty sure i would have to put something underneath to give it a cushion so it doesnt vibrate, however as far as I understand when dynamat or any equiv. product is installed it's pretty hard correct? So even if I do install it i would need something else to create a cushion?

What do you guys think?

I've read that it is usually recommended that you do the floor also, but curious to see some responses...

Lowe's has this stuff called Quik-Fix gutter repair tape. http://www.snootch420.freewebspace.com/photo.html
Whenever you install an adhesive sound-deadening product like this, it's pretty much permanent. It can be removed, but it's really really hard and messy. Use a bunch of this to deaden road noise, and if you have a nice system, keep the stereo from vibrating the car's panels. You will want to do at least two layers of the stuff to realize any audible benefits.

To answer your question, sound deaden before you install the equip you're referencing. The deadener is hard but much more of a cushion than metal. To add a suggestion to the above, you may want to try peel n seal. Also can be bought at lowe's.

I think that the Quik-Fix stuff I'm using is the same identical stuff as the Peel n' Seal, as the last time I picked some up @ Lowe's, the ID label on the shelf said Peel n' Seal. It's alot cheaper than B-quiet, Dynamat, or Brown Bread. I think each roll that I picked up was 6" wide and 20' long for approx. $13.

Thanks guys.. I actually spent about 2 or 3 hours yesterday reading some audio boards and boy is there a lot of different views on the materials. While half the people tend to recommend stuff like peal n' seal and say it works just great, the other half seems to have stories how it destroyed the cars etc.

To answer my own question, I think i will do the entire trunk floor before i start fiberglassing. Material? Well I'm going to pay my local hardware stores a visit and see what they carry first, also going to stop by some local audio shops and talk to some guys there.. See what they say.

That brings up another point though, After i lay the layer of that stuff, is it sturdy enough for me to screw into if i want to mount the fiberglass part? *I'm guessing yes it is*. Also any ideas if that might cause some problems later in terms of rattles? Should i be putting anything in between?

While half the people tend to recommend stuff like peal n' seal and say it works just great, the other half seems to have stories how it destroyed the cars etc.

yeah, the main negative remarks you hear about products like peel n' seal, is:
1) It smels like roofing tar.
2) It melts after being installed with heat from the sun.

My answers:
1) I've put quite a bit of it in my car, and I haven't smelled any kind of roofing tar smell. I honestly thought it would, but took the chance, and it doesn't smell.
2) A few weeks after it started getting pretty hot here again (90 deg. F+), I pulled up some of the carpeting in my back well. I did see a small trickle of molten material, it looked like some oil was leaking somewhere. BUT, it's under the carpeting, it's a pretty small amount, and you can't see it, unless you pull up the carpeting- so what difference does it make. Chances are that if you ask installers at local shops in your area, they will look down on using it, BUT they also probably sell Dynamat, or some other brand.

The reason I chose to go with this stuff, is because of a recommendation of an Installer friend. His word carries a lot of weight to me, bacause he's built cars featured on the cover of Car Audio and Electronics Magazine, and he has serious skills, having installed car audio for 10+ years.

Hmm.. Visited my local audio installer yesterday... The guy wanted to cut me a great deal on some 3rd hand pos no-name brand at breathtaking price of $10Can/foot. lol.

But anyway, dont remember on which site I came across this suggestion but I read that it is recommended that when you layer your material you should do it at 90 degrees to each layer... While it doesnt pose any real problems during the installation, is this really required? From what i understand, it's all tar so i dont see why a 90 degree application would benefit the installation nor hurt it. What do you think?